Etowah River at flood level (Photo by Vicki Hammond)
he Etowah River Valley lies within the Coosa River Basin. The basin makes up the northwestern corner of Georgia and the northeastern portion of Alabama. The Etowah River begins in the southern foothills of the Appalachian Mountains. The river spans over 160 miles winding south through the Blue Ridge province and continuing through the Piedmont province where it flows into Lake Allatoona, a manmade reservoir created by the damming of the Etowah River. Allatoona Dam was created in accordance with the Flood Control Acts (FCA) of 1941 and provides flood control, drinking water, and electricity to various municipalities in the area, including parts of metropolitan Atlanta. Upon leaving Lake Allatoona, the Etowah River flows westward across the Ridge and Valley province until it meets the Oostanaula River; here the two rivers converge and form the Coosa River.[1] Over the years, numerous cities have developed along the river’s path including a pre-historic Mississippian cultural community of Native Americans. Also in the region, near the city of Cartersville, Georgia, two thrust faults intersect: the Carters Dam Fault (a.k.a. Cartersville Fault) and the Emerson Fault. These faults are part of the Brevard Fault Line formed during the Allegheny orogeny in the Permian period. Because of the tectonic activity when the continent was forming, this area is geologically diverse, and was been mined extensively in the early 1800’s. Some of the minerals extracted include: iron ore, limestone, dolomite, silica, quartz, manganese, barytes, ochre, umber, and gold.[2] In fact the nation's first gold rush took place in North Georgia near Dahlogena in 1828.
Ladd's Mountain, Cartersville GA. Remnants of an abandoned mining operation. (Photo by Vicki Hammond)
Geology
The geology under the Etowah River primarily consists of schist and gneiss which are metamorphic rocks, as well as some sedimentary carbonate rocks such as limestone and dolomite. Schist is characterized by a high content of mica and tends to break in flakes. In the same areas as schist are deposits of slate and shale. Gneissic rocks are foliated like schist but have low quantities of mica. The minerals in gneiss tend to be arranged in visable bands. The Etowah River bed contains mica schist at the river's source and a mixture of several types of rocks and minerals in the Allatoona lake area. Specifically, the lake area contains amphibolitic schist, mica schist and granite gneiss and a small area of quartzite and phyllite; after the river leaves Lake Allatoona, the underlying geology changes to mostly limestone and dolomite with a band of shale near its end at the Coosa River.[3] Preview
Amicalola Falls is located in North Georgia in the City of Dawnsonville.[4] Because of the high slope gradient this waterfall is the highest in Georgia standing at 729 feet. It flows into the Amicalola River, a catalyst of the headwaters of the Etowah River. The Etowah River is a graded stream that meanders through three different types of Georgia landscapes. A graded stream is one whose slope or gradient is adjusted to balance sediment load with stream discharge. Typically a graded stream will have a steeper slope upstream giving way to a gentler slope in the down valley direction. The falls, and the surrounding area, are mountainous and are the southern most part of the Blue Ridge province. It is here, near Springer Mountain, that the Appalachian Trail begins. Dawson Forest Wildlife Management Area,City of Atlanta Tract is fifty miles north of Atlanta. Though owned by the City of Atlanta, the tract is managed by the Georgia Forestry Commission. The Amicalola River flows south through the region and joins the Etowah River which continues through the forest tract for about 4 miles. The land transitions from the Blue Ridge to the Piedmont here. Further downstream, in the flatter Piedmont region, the Etowah River was dammed, forming Lake Allatoona. The dam impounds run-off water from 1,110 square miles into the lake.[5] Besides providing water and power, Allatoona Dam reduces the frequency of flooding in the lower elevations of the Ridge and Valley province downstream from the dam. The Etowah Indian Mounds are located in the valley area by the banks of the river in Cartersville Georgia. Six mounds, a museum, and much history about the Mississippian culture that built the mounds are maintained at this site by Georgia State Parks. The Etowah flows westward from here, converging with the Oostanalula River in Rome, Georgia to form the Coosa River. The Coosa River continues onwards to Alabama and down into the Gulf of Mexico.
Overview
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Geology
The geology under the Etowah River primarily consists of schist and gneiss which are metamorphic rocks, as well as some sedimentary carbonate rocks such as limestone and dolomite. Schist is characterized by a high content of mica and tends to break in flakes. In the same areas as schist are deposits of slate and shale. Gneissic rocks are foliated like schist but have low quantities of mica. The minerals in gneiss tend to be arranged in visable bands. The Etowah River bed contains mica schist at the river's source and a mixture of several types of rocks and minerals in the Allatoona lake area. Specifically, the lake area contains amphibolitic schist, mica schist and granite gneiss and a small area of quartzite and phyllite; after the river leaves Lake Allatoona, the underlying geology changes to mostly limestone and dolomite with a band of shale near its end at the Coosa River.[3]
Preview
Amicalola Falls is located in North Georgia in the City of Dawnsonville.[4] Because of the high slope gradient this waterfall is the highest in Georgia standing at 729 feet. It flows into the Amicalola River, a catalyst of the headwaters of the Etowah River. The Etowah River is a graded stream that meanders through three different types of Georgia landscapes. A graded stream is one whose slope or gradient is adjusted to balance sediment load with stream discharge. Typically a graded stream will have a steeper slope upstream giving way to a gentler slope in the down valley direction. The falls, and the surrounding area, are mountainous and are the southern most part of the Blue Ridge province. It is here, near Springer Mountain, that the Appalachian Trail begins. Dawson Forest Wildlife Management Area, City of Atlanta Tract is fifty miles north of Atlanta. Though owned by the City of Atlanta, the tract is managed by the Georgia Forestry Commission. The Amicalola River flows south through the region and joins the Etowah River which continues through the forest tract for about 4 miles. The land transitions from the Blue Ridge to the Piedmont here. Further downstream, in the flatter Piedmont region, the Etowah River was dammed, forming Lake Allatoona. The dam impounds run-off water from 1,110 square miles into the lake.[5] Besides providing water and power, Allatoona Dam reduces the frequency of flooding in the lower elevations of the Ridge and Valley province downstream from the dam. The Etowah Indian Mounds are located in the valley area by the banks of the river in Cartersville Georgia. Six mounds, a museum, and much history about the Mississippian culture that built the mounds are maintained at this site by Georgia State Parks. The Etowah flows westward from here, converging with the Oostanalula River in Rome, Georgia to form the Coosa River. The Coosa River continues onwards to Alabama and down into the Gulf of Mexico.